Choroidal Vascular Changes May Predict Orthokeratology Treatment Efficacy

Choroidal vascular changes noted at 1-month after initiating orthokeratology treatment may serve as biomarkers of long-term treatment efficacy and help to identify individuals who can benefit from this myopia control therapy, according to research published in Eye and Vision.

Investigators included 50 children with myopia (mean age, 10.31 years; 24 boys) who were treated with orthokeratology in the prospective, cohort study. Study participants underwent subfoveal choroidal thickness, submacular total choroidal luminal area, stromal area, choroidal vascularity index (CVI), and choriocapillaris flow deficit measurements using optical coherence tomography (OCT) and OCT-angiography (OCT-A) at baseline, 1 day, 1 week, 1 month, 3 months, 6 months, 9 months, and 1 year. The study sought to identify choroidal vascular changes at 1 month following orthokeratology treatment and their association with 1-year treatment efficacy.

The 1-year ocular elongation was 0.19  mm among the cohort, the report shows. After 1 month of orthokeratology treatment, the luminal area (0.03  mm²; P <.01), stromal area (0.02 mm²; P  < .01) and subfoveal choroidal thickness (10.62 µm; P  <.001) measurements demonstrated proportional increases. Baseline CVI, 1-month luminous area change, and 1-month subfoveal choroidal thickness change were all independently associated with 1-year ocular elongation during orthokeratology treatment after adjusting for age and sex (P  < .01 for all). These variables showed an ability to discriminate children with slow ocular elongation from their peers with fast ocular elongation (area under the receiver operating characteristic curve [AUROC], 0.872; 95% CI, 0.771-0.973).

The researchers explain that the early choroidal vascular changes following orthokeratology treatment identified by the study have potentially critical implications for clinicians and myopia control management strategies.

“[Orthokeratology] treatment induces increases in choroidal vascularity and choroidal thickness as early as one month,” the study authors explain. “Such early changes can act as predictive biomarkers of myopia control efficacy over a long term. The utilization of these predictive biomarkers will help clinicians to direct the myopic individuals to appropriate levels of care to control its progression.”

Study limitations include a high loss to follow up, an inability to account for confounding factors that may affect myopia control efficacy, and failure to use a volumetric analysis to determine choroidal vascular changes.